To ask to be released from something, such as an obligation
借故推辞，谢绝：要求从某件事，如一项义务解脱出来
We were invited to stay for dinner, but we had to beg off.
我们被邀请留下来吃晚饭，但我们不得不谢绝了
(archaic)live by begging
(古)以乞讨为生
(of a fact or action) raise a question or point that has not been dealt with; invite an obvious question
（事实或行动）引发（人们考虑）尚未触及的问题；引出多数人都能想得到的问题
assume the truth of an argument or proposition to be proved, without arguing it
未经讨论就认为某一有待证明的论点或主张正确；把尚无定论（或有待证明）的事当作事实来看待；想当然，主观臆断，武断
(Austral./NZ)I beg your pardon
(澳/新西兰)对不起；请原谅
(of an article) be available for use because unwanted by others
（物品因别人不需要）随时可用